1. Field of the Invention
The present invention concerns a system for simple nucleic acid analysis.
2. Description of the Related Art
In the known systems for nucleic acid analysis, the nucleic acids are firstly bound in order to purify or isolate the analyte to be detected. The binding is usually carried out in vessels with relatively large volumes of several cm3 in order to hold the required amount of sample, binding buffer etc. for a sensitive detection. Since detection limits of 1 to 10 analytes per ml sample have to be achieved in the diagnostic field, correspondingly large amounts of sample and thus large reaction volumes are necessary for sensitive diagnostic methods. Smaller sample volumes lead to less sensitive methods and to the risk that the analyte to be detected does not happen to be present in the selected portion of the sample which is in fact positive and would lead to a false-negative diagnostic result.
On the other hand a nucleic acid amplification of the isolated DNA analyte which is required for the detection should, however, be carried out in vessels that are as small as possible in order to achieve an adequately high amplification rate. As a consequence of this contradiction the nucleic acids immobilized for purification usually have to be eluted from the binding space and transferred into an amplification space which is different from the binding space. Devices for nucleic acid analysis using multichamber systems are described for example in EP 0 754 725; WO 95/11454; U.S. Pat. No. 5,645,801; WO 97/02357; U.S. Pat. No. 5,714,380; EP 0 733 714; EP 0 674 009; U.S. Pat. No. 5,725,831; U.S. Pat. No. 5,639,428; WO 97/10056; WO 94/05414; WO 96/41864; U.S. Pat. No. 5,589,136; WO 97/00726; EP 0 838 025; WO 97/03348; EP 0 594 260; EP 0 594 259; U.S. Pat. No. 5,288,463; U.S. Pat. No. 5,422,271; U.S. Pat. No. 5,593,838; WO 93/22053; WO 93/22054; WO 93/22055; WO 93/22058 and WO 96/15269. However, these devices require transfer of the isolated nucleic acids from one vessel into another which, however, involves additional measures and a risk of losing a part of or the entire analyte to be detected or of contaminating the sample during the transfer.